The present invention relates to a microwave oven which further functions as an electric heating oven through the use of a heater means disposed within an oven cavity and, more particularly, to a timer arrangement employed within a combination microwave oven and electric heating oven.
Microwave heating cooking is usually conducted for a time period of less than 15 minutes, and electric heating cooking is usually conducted for a time period from 10 to 60 minutes. In the case when a combination microwave oven and electric heating oven is designed, a first solution would be to provide two timer motors, one for microwave heating cooking purposes and the other for electric heating cooking purposes, in order to accurately control a cooking time period. However, it is not preferable to provide two timer motors, because the system becomes large and manual operation of two timer setting knobs associated with the two timer motors becomes complicated.
Accordingly, an object of the present invention is to provide a microwave oven which further functions as an electric heating oven.
Another object of the present invention is to provide a timer arrangement which functions as a long interval timer and a short interval timer through the use of one timer motor.
Still another object of the present invention is to provide an indication means having two different time period scales associated with a long interval timer and a short interval timer, respectively.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, a selection lever is provided for selectively performing microwave heating cooking and electric heating cooking in a combination microwave oven and electric heating oven.
A switching means is associated with the selection lever so as to intermittently energize a timer motor during an electric heating cooking mode, whereby a timer arrangement associated with the timer motor functions as a long interval timer when the combination microwave oven and electric heating oven is placed in the electric heating cooking mode and the timer arrangement functions as a short interval timer when the combination microwave oven and electric heating oven is placed in a microwave heating cooking mode.
In a preferred form the switching means includes a cam mechanism driven by a turntable motor. The cam mechanism functions to intermittently energize the timer motor in the electric heating cooking mode, whereby the 15 minute timer is provided in the microwave heating cooking mode and the 60 minute timer is provided in the electric heating cooking mode through the use of one timer motor.
A timer drum having two surfaces, one including a timer scale for the 60 minute timer and the other including a timer scale for the 15 minute timer, is associated with the selection lever in such a manner that the 60 minute timer scale can be seen by the operator when the selection lever is positioned at the electric heating cooking mode, and the 15 minute timer scale can be seen by the operator when the selection lever is positioned at the microwave heating cooking mode.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.